TY - JOUR T1 - Numerical Calculations for the Length of the Transitory Zone in Partially Filled Circular Pipes with Steep Slope TT - Kısmen Dolu Yüksek Eğimli Dairesel Borularda Geçiş Bölgesi Uzunluğunun Sayısal Olarak Hesaplanması AU - Kaya, Kenan AU - Ozcan, Oktay PY - 2025 DA - April Y2 - 2025 DO - 10.2339/politeknik.1521326 JF - Politeknik Dergisi PB - Gazi University WT - DergiPark SN - 2147-9429 SP - 1 EP - 1 LA - en AB - Three-dimensional turbulent free-surface flow through smooth and corrugated circular pipes with steep slope is simulated by means of Computational Fluid Dynamics (CFD). For this purpose, the three-dimensional Reynolds Averaged Navier-Stokes equations are solved using the ANSYS Fluent solver, while interface between air and water is calculated using the Volume of Fluid (VOF) method. Effect of inlet conditions regarding the Froude and Reynolds numbers, channel slope and filling ratio on the length of flow development is investigated while both sub-critical and super-critical inlet conditions are considered. Results of the numerical calculations show that uniform open channel flow is guaranteed roughly 110 and 60 diameters downstream the pipe inlet, for smooth and corrugated pipes, respectively. The transitory length shows a tendency to decrease with the Reynolds number, contrary to the entrance length in pipe flow. KW - Uniform open-channel flow KW - smooth pipe KW - corrugated pipe KW - computational fluid dynamics KW - volume of fluid method. N2 - Yüksek eğimli pürüzsüz ve oluklu dairesel borulardaki üç boyutlu türbülanslı serbest yüzey akışı Hesaplamalı Akışkanlar Dinamiği (HAD) aracılığıyla hesaplanmıştır. 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